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   1 /*
   2  *  drivers/s390/cio/device.c
   3  *  bus driver for ccw devices
   4  *
   5  *    Copyright IBM Corp. 2002,2008
   6  *    Author(s): Arnd Bergmann (arndb@de.ibm.com)
   7  *               Cornelia Huck (cornelia.huck@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  */
  10
  11 #define KMSG_COMPONENT "cio"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/errno.h>
  18 #include <linux/err.h>
  19 #include <linux/slab.h>
  20 #include <linux/list.h>
  21 #include <linux/device.h>
  22 #include <linux/workqueue.h>
  23 #include <linux/timer.h>
  24
  25 #include <asm/ccwdev.h>
  26 #include <asm/cio.h>
  27 #include <asm/param.h>          /* HZ */
  28 #include <asm/cmb.h>
  29 #include <asm/isc.h>
  30
  31 #include "chp.h"
  32 #include "cio.h"
  33 #include "cio_debug.h"
  34 #include "css.h"
  35 #include "device.h"
  36 #include "ioasm.h"
  37 #include "io_sch.h"
  38 #include "blacklist.h"
  39
  40 static struct timer_list recovery_timer;
  41 static DEFINE_SPINLOCK(recovery_lock);
  42 static int recovery_phase;
  43 static const unsigned long recovery_delay[] = { 3, 30, 300 };
  44
  45 /******************* bus type handling ***********************/
  46
  47 /* The Linux driver model distinguishes between a bus type and
  48  * the bus itself. Of course we only have one channel
  49  * subsystem driver and one channel system per machine, but
  50  * we still use the abstraction. T.R. says it's a good idea. */
  51 static int
  52 ccw_bus_match (struct device * dev, struct device_driver * drv)
  53 {
  54         struct ccw_device *cdev = to_ccwdev(dev);
  55         struct ccw_driver *cdrv = to_ccwdrv(drv);
  56         const struct ccw_device_id *ids = cdrv->ids, *found;
  57
  58         if (!ids)
  59                 return 0;
  60
  61         found = ccw_device_id_match(ids, &cdev->id);
  62         if (!found)
  63                 return 0;
  64
  65         cdev->id.driver_info = found->driver_info;
  66
  67         return 1;
  68 }
  69
  70 /* Store modalias string delimited by prefix/suffix string into buffer with
  71  * specified size. Return length of resulting string (excluding trailing '\0')
  72  * even if string doesn't fit buffer (snprintf semantics). */
  73 static int snprint_alias(char *buf, size_t size,
  74                          struct ccw_device_id *id, const char *suffix)
  75 {
  76         int len;
  77
  78         len = snprintf(buf, size, "ccw:t%04Xm%02X", id->cu_type, id->cu_model);
  79         if (len > size)
  80                 return len;
  81         buf += len;
  82         size -= len;
  83
  84         if (id->dev_type != 0)
  85                 len += snprintf(buf, size, "dt%04Xdm%02X%s", id->dev_type,
  86                                 id->dev_model, suffix);
  87         else
  88                 len += snprintf(buf, size, "dtdm%s", suffix);
  89
  90         return len;
  91 }
  92
  93 /* Set up environment variables for ccw device uevent. Return 0 on success,
  94  * non-zero otherwise. */
  95 static int ccw_uevent(struct device *dev, struct kobj_uevent_env *env)
  96 {
  97         struct ccw_device *cdev = to_ccwdev(dev);
  98         struct ccw_device_id *id = &(cdev->id);
  99         int ret;
 100         char modalias_buf[30];
 101
 102         /* CU_TYPE= */
 103         ret = add_uevent_var(env, "CU_TYPE=%04X", id->cu_type);
 104         if (ret)
 105                 return ret;
 106
 107         /* CU_MODEL= */
 108         ret = add_uevent_var(env, "CU_MODEL=%02X", id->cu_model);
 109         if (ret)
 110                 return ret;
 111
 112         /* The next two can be zero, that's ok for us */
 113         /* DEV_TYPE= */
 114         ret = add_uevent_var(env, "DEV_TYPE=%04X", id->dev_type);
 115         if (ret)
 116                 return ret;
 117
 118         /* DEV_MODEL= */
 119         ret = add_uevent_var(env, "DEV_MODEL=%02X", id->dev_model);
 120         if (ret)
 121                 return ret;
 122
 123         /* MODALIAS=  */
 124         snprint_alias(modalias_buf, sizeof(modalias_buf), id, "");
 125         ret = add_uevent_var(env, "MODALIAS=%s", modalias_buf);
 126         return ret;
 127 }
 128
 129 struct bus_type ccw_bus_type;
 130
 131 static void io_subchannel_irq(struct subchannel *);
 132 static int io_subchannel_probe(struct subchannel *);
 133 static int io_subchannel_remove(struct subchannel *);
 134 static void io_subchannel_shutdown(struct subchannel *);
 135 static int io_subchannel_sch_event(struct subchannel *, int);
 136 static int io_subchannel_chp_event(struct subchannel *, struct chp_link *,
 137                                    int);
 138 static void recovery_func(unsigned long data);
 139 wait_queue_head_t ccw_device_init_wq;
 140 atomic_t ccw_device_init_count;
 141
 142 static struct css_device_id io_subchannel_ids[] = {
 143         { .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
 144         { /* end of list */ },
 145 };
 146 MODULE_DEVICE_TABLE(css, io_subchannel_ids);
 147
 148 static int io_subchannel_prepare(struct subchannel *sch)
 149 {
 150         struct ccw_device *cdev;
 151         /*
 152          * Don't allow suspend while a ccw device registration
 153          * is still outstanding.
 154          */
 155         cdev = sch_get_cdev(sch);
 156         if (cdev && !device_is_registered(&cdev->dev))
 157                 return -EAGAIN;
 158         return 0;
 159 }
 160
 161 static int io_subchannel_settle(void)
 162 {
 163         int ret;
 164
 165         ret = wait_event_interruptible(ccw_device_init_wq,
 166                                 atomic_read(&ccw_device_init_count) == 0);
 167         if (ret)
 168                 return -EINTR;
 169         flush_workqueue(cio_work_q);
 170         return 0;
 171 }
 172
 173 static struct css_driver io_subchannel_driver = {
 174         .owner = THIS_MODULE,
 175         .subchannel_type = io_subchannel_ids,
 176         .name = "io_subchannel",
 177         .irq = io_subchannel_irq,
 178         .sch_event = io_subchannel_sch_event,
 179         .chp_event = io_subchannel_chp_event,
 180         .probe = io_subchannel_probe,
 181         .remove = io_subchannel_remove,
 182         .shutdown = io_subchannel_shutdown,
 183         .prepare = io_subchannel_prepare,
 184         .settle = io_subchannel_settle,
 185 };
 186
 187 int __init io_subchannel_init(void)
 188 {
 189         int ret;
 190
 191         init_waitqueue_head(&ccw_device_init_wq);
 192         atomic_set(&ccw_device_init_count, 0);
 193         setup_timer(&recovery_timer, recovery_func, 0);
 194
 195         ret = bus_register(&ccw_bus_type);
 196         if (ret)
 197                 return ret;
 198         ret = css_driver_register(&io_subchannel_driver);
 199         if (ret)
 200                 bus_unregister(&ccw_bus_type);
 201
 202         return ret;
 203 }
 204
 205
 206 /************************ device handling **************************/
 207
 208 /*
 209  * A ccw_device has some interfaces in sysfs in addition to the
 210  * standard ones.
 211  * The following entries are designed to export the information which
 212  * resided in 2.4 in /proc/subchannels. Subchannel and device number
 213  * are obvious, so they don't have an entry :)
 214  * TODO: Split chpids and pimpampom up? Where is "in use" in the tree?
 215  */
 216 static ssize_t
 217 chpids_show (struct device * dev, struct device_attribute *attr, char * buf)
 218 {
 219         struct subchannel *sch = to_subchannel(dev);
 220         struct chsc_ssd_info *ssd = &sch->ssd_info;
 221         ssize_t ret = 0;
 222         int chp;
 223         int mask;
 224
 225         for (chp = 0; chp < 8; chp++) {
 226                 mask = 0x80 >> chp;
 227                 if (ssd->path_mask & mask)
 228                         ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
 229                 else
 230                         ret += sprintf(buf + ret, "00 ");
 231         }
 232         ret += sprintf (buf+ret, "\n");
 233         return min((ssize_t)PAGE_SIZE, ret);
 234 }
 235
 236 static ssize_t
 237 pimpampom_show (struct device * dev, struct device_attribute *attr, char * buf)
 238 {
 239         struct subchannel *sch = to_subchannel(dev);
 240         struct pmcw *pmcw = &sch->schib.pmcw;
 241
 242         return sprintf (buf, "%02x %02x %02x\n",
 243                         pmcw->pim, pmcw->pam, pmcw->pom);
 244 }
 245
 246 static ssize_t
 247 devtype_show (struct device *dev, struct device_attribute *attr, char *buf)
 248 {
 249         struct ccw_device *cdev = to_ccwdev(dev);
 250         struct ccw_device_id *id = &(cdev->id);
 251
 252         if (id->dev_type != 0)
 253                 return sprintf(buf, "%04x/%02x\n",
 254                                 id->dev_type, id->dev_model);
 255         else
 256                 return sprintf(buf, "n/a\n");
 257 }
 258
 259 static ssize_t
 260 cutype_show (struct device *dev, struct device_attribute *attr, char *buf)
 261 {
 262         struct ccw_device *cdev = to_ccwdev(dev);
 263         struct ccw_device_id *id = &(cdev->id);
 264
 265         return sprintf(buf, "%04x/%02x\n",
 266                        id->cu_type, id->cu_model);
 267 }
 268
 269 static ssize_t
 270 modalias_show (struct device *dev, struct device_attribute *attr, char *buf)
 271 {
 272         struct ccw_device *cdev = to_ccwdev(dev);
 273         struct ccw_device_id *id = &(cdev->id);
 274         int len;
 275
 276         len = snprint_alias(buf, PAGE_SIZE, id, "\n");
 277
 278         return len > PAGE_SIZE ? PAGE_SIZE : len;
 279 }
 280
 281 static ssize_t
 282 online_show (struct device *dev, struct device_attribute *attr, char *buf)
 283 {
 284         struct ccw_device *cdev = to_ccwdev(dev);
 285
 286         return sprintf(buf, cdev->online ? "1\n" : "0\n");
 287 }
 288
 289 int ccw_device_is_orphan(struct ccw_device *cdev)
 290 {
 291         return sch_is_pseudo_sch(to_subchannel(cdev->dev.parent));
 292 }
 293
 294 static void ccw_device_unregister(struct ccw_device *cdev)
 295 {
 296         if (device_is_registered(&cdev->dev)) {
 297                 /* Undo device_add(). */
 298                 device_del(&cdev->dev);
 299         }
 300         if (cdev->private->flags.initialized) {
 301                 cdev->private->flags.initialized = 0;
 302                 /* Release reference from device_initialize(). */
 303                 put_device(&cdev->dev);
 304         }
 305 }
 306
 307 static void io_subchannel_quiesce(struct subchannel *);
 308
 309 /**
 310  * ccw_device_set_offline() - disable a ccw device for I/O
 311  * @cdev: target ccw device
 312  *
 313  * This function calls the driver's set_offline() function for @cdev, if
 314  * given, and then disables @cdev.
 315  * Returns:
 316  *   %0 on success and a negative error value on failure.
 317  * Context:
 318  *  enabled, ccw device lock not held
 319  */
 320 int ccw_device_set_offline(struct ccw_device *cdev)
 321 {
 322         struct subchannel *sch;
 323         int ret, state;
 324
 325         if (!cdev)
 326                 return -ENODEV;
 327         if (!cdev->online || !cdev->drv)
 328                 return -EINVAL;
 329
 330         if (cdev->drv->set_offline) {
 331                 ret = cdev->drv->set_offline(cdev);
 332                 if (ret != 0)
 333                         return ret;
 334         }
 335         cdev->online = 0;
 336         spin_lock_irq(cdev->ccwlock);
 337         sch = to_subchannel(cdev->dev.parent);
 338         /* Wait until a final state or DISCONNECTED is reached */
 339         while (!dev_fsm_final_state(cdev) &&
 340                cdev->private->state != DEV_STATE_DISCONNECTED) {
 341                 spin_unlock_irq(cdev->ccwlock);
 342                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 343                            cdev->private->state == DEV_STATE_DISCONNECTED));
 344                 spin_lock_irq(cdev->ccwlock);
 345         }
 346         do {
 347                 ret = ccw_device_offline(cdev);
 348                 if (!ret)
 349                         break;
 350                 CIO_MSG_EVENT(0, "ccw_device_offline returned %d, device "
 351                               "0.%x.%04x\n", ret, cdev->private->dev_id.ssid,
 352                               cdev->private->dev_id.devno);
 353                 if (ret != -EBUSY)
 354                         goto error;
 355                 state = cdev->private->state;
 356                 spin_unlock_irq(cdev->ccwlock);
 357                 io_subchannel_quiesce(sch);
 358                 spin_lock_irq(cdev->ccwlock);
 359                 cdev->private->state = state;
 360         } while (ret == -EBUSY);
 361         spin_unlock_irq(cdev->ccwlock);
 362         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 363                    cdev->private->state == DEV_STATE_DISCONNECTED));
 364         /* Inform the user if set offline failed. */
 365         if (cdev->private->state == DEV_STATE_BOXED) {
 366                 pr_warning("%s: The device entered boxed state while "
 367                            "being set offline\n", dev_name(&cdev->dev));
 368         } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 369                 pr_warning("%s: The device stopped operating while "
 370                            "being set offline\n", dev_name(&cdev->dev));
 371         }
 372         /* Give up reference from ccw_device_set_online(). */
 373         put_device(&cdev->dev);
 374         return 0;
 375
 376 error:
 377         cdev->private->state = DEV_STATE_OFFLINE;
 378         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
 379         spin_unlock_irq(cdev->ccwlock);
 380         /* Give up reference from ccw_device_set_online(). */
 381         put_device(&cdev->dev);
 382         return -ENODEV;
 383 }
 384
 385 /**
 386  * ccw_device_set_online() - enable a ccw device for I/O
 387  * @cdev: target ccw device
 388  *
 389  * This function first enables @cdev and then calls the driver's set_online()
 390  * function for @cdev, if given. If set_online() returns an error, @cdev is
 391  * disabled again.
 392  * Returns:
 393  *   %0 on success and a negative error value on failure.
 394  * Context:
 395  *  enabled, ccw device lock not held
 396  */
 397 int ccw_device_set_online(struct ccw_device *cdev)
 398 {
 399         int ret;
 400         int ret2;
 401
 402         if (!cdev)
 403                 return -ENODEV;
 404         if (cdev->online || !cdev->drv)
 405                 return -EINVAL;
 406         /* Hold on to an extra reference while device is online. */
 407         if (!get_device(&cdev->dev))
 408                 return -ENODEV;
 409
 410         spin_lock_irq(cdev->ccwlock);
 411         ret = ccw_device_online(cdev);
 412         spin_unlock_irq(cdev->ccwlock);
 413         if (ret == 0)
 414                 wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
 415         else {
 416                 CIO_MSG_EVENT(0, "ccw_device_online returned %d, "
 417                               "device 0.%x.%04x\n",
 418                               ret, cdev->private->dev_id.ssid,
 419                               cdev->private->dev_id.devno);
 420                 /* Give up online reference since onlining failed. */
 421                 put_device(&cdev->dev);
 422                 return ret;
 423         }
 424         spin_lock_irq(cdev->ccwlock);
 425         /* Check if online processing was successful */
 426         if ((cdev->private->state != DEV_STATE_ONLINE) &&
 427             (cdev->private->state != DEV_STATE_W4SENSE)) {
 428                 spin_unlock_irq(cdev->ccwlock);
 429                 /* Inform the user that set online failed. */
 430                 if (cdev->private->state == DEV_STATE_BOXED) {
 431                         pr_warning("%s: Setting the device online failed "
 432                                    "because it is boxed\n",
 433                                    dev_name(&cdev->dev));
 434                 } else if (cdev->private->state == DEV_STATE_NOT_OPER) {
 435                         pr_warning("%s: Setting the device online failed "
 436                                    "because it is not operational\n",
 437                                    dev_name(&cdev->dev));
 438                 }
 439                 /* Give up online reference since onlining failed. */
 440                 put_device(&cdev->dev);
 441                 return -ENODEV;
 442         }
 443         spin_unlock_irq(cdev->ccwlock);
 444         if (cdev->drv->set_online)
 445                 ret = cdev->drv->set_online(cdev);
 446         if (ret)
 447                 goto rollback;
 448         cdev->online = 1;
 449         return 0;
 450
 451 rollback:
 452         spin_lock_irq(cdev->ccwlock);
 453         /* Wait until a final state or DISCONNECTED is reached */
 454         while (!dev_fsm_final_state(cdev) &&
 455                cdev->private->state != DEV_STATE_DISCONNECTED) {
 456                 spin_unlock_irq(cdev->ccwlock);
 457                 wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 458                            cdev->private->state == DEV_STATE_DISCONNECTED));
 459                 spin_lock_irq(cdev->ccwlock);
 460         }
 461         ret2 = ccw_device_offline(cdev);
 462         if (ret2)
 463                 goto error;
 464         spin_unlock_irq(cdev->ccwlock);
 465         wait_event(cdev->private->wait_q, (dev_fsm_final_state(cdev) ||
 466                    cdev->private->state == DEV_STATE_DISCONNECTED));
 467         /* Give up online reference since onlining failed. */
 468         put_device(&cdev->dev);
 469         return ret;
 470
 471 error:
 472         CIO_MSG_EVENT(0, "rollback ccw_device_offline returned %d, "
 473                       "device 0.%x.%04x\n",
 474                       ret2, cdev->private->dev_id.ssid,
 475                       cdev->private->dev_id.devno);
 476         cdev->private->state = DEV_STATE_OFFLINE;
 477         spin_unlock_irq(cdev->ccwlock);
 478         /* Give up online reference since onlining failed. */
 479         put_device(&cdev->dev);
 480         return ret;
 481 }
 482
 483 static int online_store_handle_offline(struct ccw_device *cdev)
 484 {
 485         if (cdev->private->state == DEV_STATE_DISCONNECTED) {
 486                 spin_lock_irq(cdev->ccwlock);
 487                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG_EVAL);
 488                 spin_unlock_irq(cdev->ccwlock);
 489         } else if (cdev->online && cdev->drv && cdev->drv->set_offline)
 490                 return ccw_device_set_offline(cdev);
 491         return 0;
 492 }
 493
 494 static int online_store_recog_and_online(struct ccw_device *cdev)
 495 {
 496         /* Do device recognition, if needed. */
 497         if (cdev->private->state == DEV_STATE_BOXED) {
 498                 spin_lock_irq(cdev->ccwlock);
 499                 ccw_device_recognition(cdev);
 500                 spin_unlock_irq(cdev->ccwlock);
 501                 wait_event(cdev->private->wait_q,
 502                            cdev->private->flags.recog_done);
 503                 if (cdev->private->state != DEV_STATE_OFFLINE)
 504                         /* recognition failed */
 505                         return -EAGAIN;
 506         }
 507         if (cdev->drv && cdev->drv->set_online)
 508                 ccw_device_set_online(cdev);
 509         return 0;
 510 }
 511
 512 static int online_store_handle_online(struct ccw_device *cdev, int force)
 513 {
 514         int ret;
 515
 516         ret = online_store_recog_and_online(cdev);
 517         if (ret && !force)
 518                 return ret;
 519         if (force && cdev->private->state == DEV_STATE_BOXED) {
 520                 ret = ccw_device_stlck(cdev);
 521                 if (ret)
 522                         return ret;
 523                 if (cdev->id.cu_type == 0)
 524                         cdev->private->state = DEV_STATE_NOT_OPER;
 525                 ret = online_store_recog_and_online(cdev);
 526                 if (ret)
 527                         return ret;
 528         }
 529         return 0;
 530 }
 531
 532 static ssize_t online_store (struct device *dev, struct device_attribute *attr,
 533                              const char *buf, size_t count)
 534 {
 535         struct ccw_device *cdev = to_ccwdev(dev);
 536         int force, ret;
 537         unsigned long i;
 538
 539         if (!dev_fsm_final_state(cdev) &&
 540             cdev->private->state != DEV_STATE_DISCONNECTED)
 541                 return -EAGAIN;
 542         if (atomic_cmpxchg(&cdev->private->onoff, 0, 1) != 0)
 543                 return -EAGAIN;
 544
 545         if (cdev->drv && !try_module_get(cdev->drv->owner)) {
 546                 atomic_set(&cdev->private->onoff, 0);
 547                 return -EINVAL;
 548         }
 549         if (!strncmp(buf, "force\n", count)) {
 550                 force = 1;
 551                 i = 1;
 552                 ret = 0;
 553         } else {
 554                 force = 0;
 555                 ret = strict_strtoul(buf, 16, &i);
 556         }
 557         if (ret)
 558                 goto out;
 559         switch (i) {
 560         case 0:
 561                 ret = online_store_handle_offline(cdev);
 562                 break;
 563         case 1:
 564                 ret = online_store_handle_online(cdev, force);
 565                 break;
 566         default:
 567                 ret = -EINVAL;
 568         }
 569 out:
 570         if (cdev->drv)
 571                 module_put(cdev->drv->owner);
 572         atomic_set(&cdev->private->onoff, 0);
 573         return (ret < 0) ? ret : count;
 574 }
 575
 576 static ssize_t
 577 available_show (struct device *dev, struct device_attribute *attr, char *buf)
 578 {
 579         struct ccw_device *cdev = to_ccwdev(dev);
 580         struct subchannel *sch;
 581
 582         if (ccw_device_is_orphan(cdev))
 583                 return sprintf(buf, "no device\n");
 584         switch (cdev->private->state) {
 585         case DEV_STATE_BOXED:
 586                 return sprintf(buf, "boxed\n");
 587         case DEV_STATE_DISCONNECTED:
 588         case DEV_STATE_DISCONNECTED_SENSE_ID:
 589         case DEV_STATE_NOT_OPER:
 590                 sch = to_subchannel(dev->parent);
 591                 if (!sch->lpm)
 592                         return sprintf(buf, "no path\n");
 593                 else
 594                         return sprintf(buf, "no device\n");
 595         default:
 596                 /* All other states considered fine. */
 597                 return sprintf(buf, "good\n");
 598         }
 599 }
 600
 601 static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
 602 static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
 603 static DEVICE_ATTR(devtype, 0444, devtype_show, NULL);
 604 static DEVICE_ATTR(cutype, 0444, cutype_show, NULL);
 605 static DEVICE_ATTR(modalias, 0444, modalias_show, NULL);
 606 static DEVICE_ATTR(online, 0644, online_show, online_store);
 607 static DEVICE_ATTR(availability, 0444, available_show, NULL);
 608
 609 static struct attribute *io_subchannel_attrs[] = {
 610         &dev_attr_chpids.attr,
 611         &dev_attr_pimpampom.attr,
 612         NULL,
 613 };
 614
 615 static struct attribute_group io_subchannel_attr_group = {
 616         .attrs = io_subchannel_attrs,
 617 };
 618
 619 static struct attribute * ccwdev_attrs[] = {
 620         &dev_attr_devtype.attr,
 621         &dev_attr_cutype.attr,
 622         &dev_attr_modalias.attr,
 623         &dev_attr_online.attr,
 624         &dev_attr_cmb_enable.attr,
 625         &dev_attr_availability.attr,
 626         NULL,
 627 };
 628
 629 static struct attribute_group ccwdev_attr_group = {
 630         .attrs = ccwdev_attrs,
 631 };
 632
 633 static const struct attribute_group *ccwdev_attr_groups[] = {
 634         &ccwdev_attr_group,
 635         NULL,
 636 };
 637
 638 /* this is a simple abstraction for device_register that sets the
 639  * correct bus type and adds the bus specific files */
 640 static int ccw_device_register(struct ccw_device *cdev)
 641 {
 642         struct device *dev = &cdev->dev;
 643         int ret;
 644
 645         dev->bus = &ccw_bus_type;
 646         ret = dev_set_name(&cdev->dev, "0.%x.%04x", cdev->private->dev_id.ssid,
 647                            cdev->private->dev_id.devno);
 648         if (ret)
 649                 return ret;
 650         return device_add(dev);
 651 }
 652
 653 static int match_dev_id(struct device *dev, void *data)
 654 {
 655         struct ccw_device *cdev = to_ccwdev(dev);
 656         struct ccw_dev_id *dev_id = data;
 657
 658         return ccw_dev_id_is_equal(&cdev->private->dev_id, dev_id);
 659 }
 660
 661 static struct ccw_device *get_ccwdev_by_dev_id(struct ccw_dev_id *dev_id)
 662 {
 663         struct device *dev;
 664
 665         dev = bus_find_device(&ccw_bus_type, NULL, dev_id, match_dev_id);
 666
 667         return dev ? to_ccwdev(dev) : NULL;
 668 }
 669
 670 static void ccw_device_do_unbind_bind(struct ccw_device *cdev)
 671 {
 672         int ret;
 673
 674         if (device_is_registered(&cdev->dev)) {
 675                 device_release_driver(&cdev->dev);
 676                 ret = device_attach(&cdev->dev);
 677                 WARN_ON(ret == -ENODEV);
 678         }
 679 }
 680
 681 static void
 682 ccw_device_release(struct device *dev)
 683 {
 684         struct ccw_device *cdev;
 685
 686         cdev = to_ccwdev(dev);
 687         /* Release reference of parent subchannel. */
 688         put_device(cdev->dev.parent);
 689         kfree(cdev->private);
 690         kfree(cdev);
 691 }
 692
 693 static struct ccw_device * io_subchannel_allocate_dev(struct subchannel *sch)
 694 {
 695         struct ccw_device *cdev;
 696
 697         cdev  = kzalloc(sizeof(*cdev), GFP_KERNEL);
 698         if (cdev) {
 699                 cdev->private = kzalloc(sizeof(struct ccw_device_private),
 700                                         GFP_KERNEL | GFP_DMA);
 701                 if (cdev->private)
 702                         return cdev;
 703         }
 704         kfree(cdev);
 705         return ERR_PTR(-ENOMEM);
 706 }
 707
 708 static void ccw_device_todo(struct work_struct *work);
 709
 710 static int io_subchannel_initialize_dev(struct subchannel *sch,
 711                                         struct ccw_device *cdev)
 712 {
 713         cdev->private->cdev = cdev;
 714         atomic_set(&cdev->private->onoff, 0);
 715         cdev->dev.parent = &sch->dev;
 716         cdev->dev.release = ccw_device_release;
 717         INIT_WORK(&cdev->private->todo_work, ccw_device_todo);
 718         cdev->dev.groups = ccwdev_attr_groups;
 719         /* Do first half of device_register. */
 720         device_initialize(&cdev->dev);
 721         if (!get_device(&sch->dev)) {
 722                 /* Release reference from device_initialize(). */
 723                 put_device(&cdev->dev);
 724                 return -ENODEV;
 725         }
 726         cdev->private->flags.initialized = 1;
 727         return 0;
 728 }
 729
 730 static struct ccw_device * io_subchannel_create_ccwdev(struct subchannel *sch)
 731 {
 732         struct ccw_device *cdev;
 733         int ret;
 734
 735         cdev = io_subchannel_allocate_dev(sch);
 736         if (!IS_ERR(cdev)) {
 737                 ret = io_subchannel_initialize_dev(sch, cdev);
 738                 if (ret)
 739                         cdev = ERR_PTR(ret);
 740         }
 741         return cdev;
 742 }
 743
 744 static void io_subchannel_recog(struct ccw_device *, struct subchannel *);
 745
 746 static void sch_create_and_recog_new_device(struct subchannel *sch)
 747 {
 748         struct ccw_device *cdev;
 749
 750         /* Need to allocate a new ccw device. */
 751         cdev = io_subchannel_create_ccwdev(sch);
 752         if (IS_ERR(cdev)) {
 753                 /* OK, we did everything we could... */
 754                 css_sch_device_unregister(sch);
 755                 return;
 756         }
 757         /* Start recognition for the new ccw device. */
 758         io_subchannel_recog(cdev, sch);
 759 }
 760
 761 /*
 762  * Register recognized device.
 763  */
 764 static void io_subchannel_register(struct ccw_device *cdev)
 765 {
 766         struct subchannel *sch;
 767         int ret, adjust_init_count = 1;
 768         unsigned long flags;
 769
 770         sch = to_subchannel(cdev->dev.parent);
 771         /*
 772          * Check if subchannel is still registered. It may have become
 773          * unregistered if a machine check hit us after finishing
 774          * device recognition but before the register work could be
 775          * queued.
 776          */
 777         if (!device_is_registered(&sch->dev))
 778                 goto out_err;
 779         css_update_ssd_info(sch);
 780         /*
 781          * io_subchannel_register() will also be called after device
 782          * recognition has been done for a boxed device (which will already
 783          * be registered). We need to reprobe since we may now have sense id
 784          * information.
 785          */
 786         if (device_is_registered(&cdev->dev)) {
 787                 if (!cdev->drv) {
 788                         ret = device_reprobe(&cdev->dev);
 789                         if (ret)
 790                                 /* We can't do much here. */
 791                                 CIO_MSG_EVENT(0, "device_reprobe() returned"
 792                                               " %d for 0.%x.%04x\n", ret,
 793                                               cdev->private->dev_id.ssid,
 794                                               cdev->private->dev_id.devno);
 795                 }
 796                 adjust_init_count = 0;
 797                 goto out;
 798         }
 799         /*
 800          * Now we know this subchannel will stay, we can throw
 801          * our delayed uevent.
 802          */
 803         dev_set_uevent_suppress(&sch->dev, 0);
 804         kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
 805         /* make it known to the system */
 806         ret = ccw_device_register(cdev);
 807         if (ret) {
 808                 CIO_MSG_EVENT(0, "Could not register ccw dev 0.%x.%04x: %d\n",
 809                               cdev->private->dev_id.ssid,
 810                               cdev->private->dev_id.devno, ret);
 811                 spin_lock_irqsave(sch->lock, flags);
 812                 sch_set_cdev(sch, NULL);
 813                 spin_unlock_irqrestore(sch->lock, flags);
 814                 /* Release initial device reference. */
 815                 put_device(&cdev->dev);
 816                 goto out_err;
 817         }
 818 out:
 819         cdev->private->flags.recog_done = 1;
 820         wake_up(&cdev->private->wait_q);
 821 out_err:
 822         if (adjust_init_count && atomic_dec_and_test(&ccw_device_init_count))
 823                 wake_up(&ccw_device_init_wq);
 824 }
 825
 826 static void ccw_device_call_sch_unregister(struct ccw_device *cdev)
 827 {
 828         struct subchannel *sch;
 829
 830         /* Get subchannel reference for local processing. */
 831         if (!get_device(cdev->dev.parent))
 832                 return;
 833         sch = to_subchannel(cdev->dev.parent);
 834         css_sch_device_unregister(sch);
 835         /* Release subchannel reference for local processing. */
 836         put_device(&sch->dev);
 837 }
 838
 839 /*
 840  * subchannel recognition done. Called from the state machine.
 841  */
 842 void
 843 io_subchannel_recog_done(struct ccw_device *cdev)
 844 {
 845         if (css_init_done == 0) {
 846                 cdev->private->flags.recog_done = 1;
 847                 return;
 848         }
 849         switch (cdev->private->state) {
 850         case DEV_STATE_BOXED:
 851                 /* Device did not respond in time. */
 852         case DEV_STATE_NOT_OPER:
 853                 cdev->private->flags.recog_done = 1;
 854                 /* Remove device found not operational. */
 855                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
 856                 if (atomic_dec_and_test(&ccw_device_init_count))
 857                         wake_up(&ccw_device_init_wq);
 858                 break;
 859         case DEV_STATE_OFFLINE:
 860                 /*
 861                  * We can't register the device in interrupt context so
 862                  * we schedule a work item.
 863                  */
 864                 ccw_device_sched_todo(cdev, CDEV_TODO_REGISTER);
 865                 break;
 866         }
 867 }
 868
 869 static void io_subchannel_recog(struct ccw_device *cdev, struct subchannel *sch)
 870 {
 871         struct ccw_device_private *priv;
 872
 873         cdev->ccwlock = sch->lock;
 874
 875         /* Init private data. */
 876         priv = cdev->private;
 877         priv->dev_id.devno = sch->schib.pmcw.dev;
 878         priv->dev_id.ssid = sch->schid.ssid;
 879         priv->schid = sch->schid;
 880         priv->state = DEV_STATE_NOT_OPER;
 881         INIT_LIST_HEAD(&priv->cmb_list);
 882         init_waitqueue_head(&priv->wait_q);
 883         init_timer(&priv->timer);
 884
 885         /* Increase counter of devices currently in recognition. */
 886         atomic_inc(&ccw_device_init_count);
 887
 888         /* Start async. device sensing. */
 889         spin_lock_irq(sch->lock);
 890         sch_set_cdev(sch, cdev);
 891         ccw_device_recognition(cdev);
 892         spin_unlock_irq(sch->lock);
 893 }
 894
 895 static int ccw_device_move_to_sch(struct ccw_device *cdev,
 896                                   struct subchannel *sch)
 897 {
 898         struct subchannel *old_sch;
 899         int rc, old_enabled = 0;
 900
 901         old_sch = to_subchannel(cdev->dev.parent);
 902         /* Obtain child reference for new parent. */
 903         if (!get_device(&sch->dev))
 904                 return -ENODEV;
 905
 906         if (!sch_is_pseudo_sch(old_sch)) {
 907                 spin_lock_irq(old_sch->lock);
 908                 old_enabled = old_sch->schib.pmcw.ena;
 909                 rc = 0;
 910                 if (old_enabled)
 911                         rc = cio_disable_subchannel(old_sch);
 912                 spin_unlock_irq(old_sch->lock);
 913                 if (rc == -EBUSY) {
 914                         /* Release child reference for new parent. */
 915                         put_device(&sch->dev);
 916                         return rc;
 917                 }
 918         }
 919
 920         mutex_lock(&sch->reg_mutex);
 921         rc = device_move(&cdev->dev, &sch->dev, DPM_ORDER_PARENT_BEFORE_DEV);
 922         mutex_unlock(&sch->reg_mutex);
 923         if (rc) {
 924                 CIO_MSG_EVENT(0, "device_move(0.%x.%04x,0.%x.%04x)=%d\n",
 925                               cdev->private->dev_id.ssid,
 926                               cdev->private->dev_id.devno, sch->schid.ssid,
 927                               sch->schib.pmcw.dev, rc);
 928                 if (old_enabled) {
 929                         /* Try to reenable the old subchannel. */
 930                         spin_lock_irq(old_sch->lock);
 931                         cio_enable_subchannel(old_sch, (u32)(addr_t)old_sch);
 932                         spin_unlock_irq(old_sch->lock);
 933                 }
 934                 /* Release child reference for new parent. */
 935                 put_device(&sch->dev);
 936                 return rc;
 937         }
 938         /* Clean up old subchannel. */
 939         if (!sch_is_pseudo_sch(old_sch)) {
 940                 spin_lock_irq(old_sch->lock);
 941                 sch_set_cdev(old_sch, NULL);
 942                 spin_unlock_irq(old_sch->lock);
 943                 css_schedule_eval(old_sch->schid);
 944         }
 945         /* Release child reference for old parent. */
 946         put_device(&old_sch->dev);
 947         /* Initialize new subchannel. */
 948         spin_lock_irq(sch->lock);
 949         cdev->private->schid = sch->schid;
 950         cdev->ccwlock = sch->lock;
 951         if (!sch_is_pseudo_sch(sch))
 952                 sch_set_cdev(sch, cdev);
 953         spin_unlock_irq(sch->lock);
 954         if (!sch_is_pseudo_sch(sch))
 955                 css_update_ssd_info(sch);
 956         return 0;
 957 }
 958
 959 static int ccw_device_move_to_orph(struct ccw_device *cdev)
 960 {
 961         struct subchannel *sch = to_subchannel(cdev->dev.parent);
 962         struct channel_subsystem *css = to_css(sch->dev.parent);
 963
 964         return ccw_device_move_to_sch(cdev, css->pseudo_subchannel);
 965 }
 966
 967 static void io_subchannel_irq(struct subchannel *sch)
 968 {
 969         struct ccw_device *cdev;
 970
 971         cdev = sch_get_cdev(sch);
 972
 973         CIO_TRACE_EVENT(6, "IRQ");
 974         CIO_TRACE_EVENT(6, dev_name(&sch->dev));
 975         if (cdev)
 976                 dev_fsm_event(cdev, DEV_EVENT_INTERRUPT);
 977 }
 978
 979 void io_subchannel_init_config(struct subchannel *sch)
 980 {
 981         memset(&sch->config, 0, sizeof(sch->config));
 982         sch->config.csense = 1;
 983 }
 984
 985 static void io_subchannel_init_fields(struct subchannel *sch)
 986 {
 987         if (cio_is_console(sch->schid))
 988                 sch->opm = 0xff;
 989         else
 990                 sch->opm = chp_get_sch_opm(sch);
 991         sch->lpm = sch->schib.pmcw.pam & sch->opm;
 992         sch->isc = cio_is_console(sch->schid) ? CONSOLE_ISC : IO_SCH_ISC;
 993
 994         CIO_MSG_EVENT(6, "Detected device %04x on subchannel 0.%x.%04X"
 995                       " - PIM = %02X, PAM = %02X, POM = %02X\n",
 996                       sch->schib.pmcw.dev, sch->schid.ssid,
 997                       sch->schid.sch_no, sch->schib.pmcw.pim,
 998                       sch->schib.pmcw.pam, sch->schib.pmcw.pom);
 999
1000         io_subchannel_init_config(sch);
1001 }
1002
1003 /*
1004  * Note: We always return 0 so that we bind to the device even on error.
1005  * This is needed so that our remove function is called on unregister.
1006  */
1007 static int io_subchannel_probe(struct subchannel *sch)
1008 {
1009         struct ccw_device *cdev;
1010         int rc;
1011
1012         if (cio_is_console(sch->schid)) {
1013                 rc = sysfs_create_group(&sch->dev.kobj,
1014                                         &io_subchannel_attr_group);
1015                 if (rc)
1016                         CIO_MSG_EVENT(0, "Failed to create io subchannel "
1017                                       "attributes for subchannel "
1018                                       "0.%x.%04x (rc=%d)\n",
1019                                       sch->schid.ssid, sch->schid.sch_no, rc);
1020                 /*
1021                  * The console subchannel already has an associated ccw_device.
1022                  * Throw the delayed uevent for the subchannel, register
1023                  * the ccw_device and exit.
1024                  */
1025                 dev_set_uevent_suppress(&sch->dev, 0);
1026                 kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
1027                 cdev = sch_get_cdev(sch);
1028                 cdev->dev.groups = ccwdev_attr_groups;
1029                 device_initialize(&cdev->dev);
1030                 cdev->private->flags.initialized = 1;
1031                 ccw_device_register(cdev);
1032                 /*
1033                  * Check if the device is already online. If it is
1034                  * the reference count needs to be corrected since we
1035                  * didn't obtain a reference in ccw_device_set_online.
1036                  */
1037                 if (cdev->private->state != DEV_STATE_NOT_OPER &&
1038                     cdev->private->state != DEV_STATE_OFFLINE &&
1039                     cdev->private->state != DEV_STATE_BOXED)
1040                         get_device(&cdev->dev);
1041                 return 0;
1042         }
1043         io_subchannel_init_fields(sch);
1044         rc = cio_commit_config(sch);
1045         if (rc)
1046                 goto out_schedule;
1047         rc = sysfs_create_group(&sch->dev.kobj,
1048                                 &io_subchannel_attr_group);
1049         if (rc)
1050                 goto out_schedule;
1051         /* Allocate I/O subchannel private data. */
1052         sch->private = kzalloc(sizeof(struct io_subchannel_private),
1053                                GFP_KERNEL | GFP_DMA);
1054         if (!sch->private)
1055                 goto out_schedule;
1056         css_schedule_eval(sch->schid);
1057         return 0;
1058
1059 out_schedule:
1060         spin_lock_irq(sch->lock);
1061         css_sched_sch_todo(sch, SCH_TODO_UNREG);
1062         spin_unlock_irq(sch->lock);
1063         return 0;
1064 }
1065
1066 static int
1067 io_subchannel_remove (struct subchannel *sch)
1068 {
1069         struct ccw_device *cdev;
1070
1071         cdev = sch_get_cdev(sch);
1072         if (!cdev)
1073                 goto out_free;
1074         io_subchannel_quiesce(sch);
1075         /* Set ccw device to not operational and drop reference. */
1076         spin_lock_irq(cdev->ccwlock);
1077         sch_set_cdev(sch, NULL);
1078         cdev->private->state = DEV_STATE_NOT_OPER;
1079         spin_unlock_irq(cdev->ccwlock);
1080         ccw_device_unregister(cdev);
1081 out_free:
1082         kfree(sch->private);
1083         sysfs_remove_group(&sch->dev.kobj, &io_subchannel_attr_group);
1084         return 0;
1085 }
1086
1087 static void io_subchannel_verify(struct subchannel *sch)
1088 {
1089         struct ccw_device *cdev;
1090
1091         cdev = sch_get_cdev(sch);
1092         if (cdev)
1093                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1094 }
1095
1096 static void io_subchannel_terminate_path(struct subchannel *sch, u8 mask)
1097 {
1098         struct ccw_device *cdev;
1099
1100         cdev = sch_get_cdev(sch);
1101         if (!cdev)
1102                 return;
1103         if (cio_update_schib(sch))
1104                 goto err;
1105         /* Check for I/O on path. */
1106         if (scsw_actl(&sch->schib.scsw) == 0 || sch->schib.pmcw.lpum != mask)
1107                 goto out;
1108         if (cdev->private->state == DEV_STATE_ONLINE) {
1109                 ccw_device_kill_io(cdev);
1110                 goto out;
1111         }
1112         if (cio_clear(sch))
1113                 goto err;
1114 out:
1115         /* Trigger path verification. */
1116         dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1117         return;
1118
1119 err:
1120         dev_fsm_event(cdev, DEV_EVENT_NOTOPER);
1121 }
1122
1123 static int io_subchannel_chp_event(struct subchannel *sch,
1124                                    struct chp_link *link, int event)
1125 {
1126         int mask;
1127
1128         mask = chp_ssd_get_mask(&sch->ssd_info, link);
1129         if (!mask)
1130                 return 0;
1131         switch (event) {
1132         case CHP_VARY_OFF:
1133                 sch->opm &= ~mask;
1134                 sch->lpm &= ~mask;
1135                 io_subchannel_terminate_path(sch, mask);
1136                 break;
1137         case CHP_VARY_ON:
1138                 sch->opm |= mask;
1139                 sch->lpm |= mask;
1140                 io_subchannel_verify(sch);
1141                 break;
1142         case CHP_OFFLINE:
1143                 if (cio_update_schib(sch))
1144                         return -ENODEV;
1145                 io_subchannel_terminate_path(sch, mask);
1146                 break;
1147         case CHP_ONLINE:
1148                 if (cio_update_schib(sch))
1149                         return -ENODEV;
1150                 sch->lpm |= mask & sch->opm;
1151                 io_subchannel_verify(sch);
1152                 break;
1153         }
1154         return 0;
1155 }
1156
1157 static void io_subchannel_quiesce(struct subchannel *sch)
1158 {
1159         struct ccw_device *cdev;
1160         int ret;
1161
1162         spin_lock_irq(sch->lock);
1163         cdev = sch_get_cdev(sch);
1164         if (cio_is_console(sch->schid))
1165                 goto out_unlock;
1166         if (!sch->schib.pmcw.ena)
1167                 goto out_unlock;
1168         ret = cio_disable_subchannel(sch);
1169         if (ret != -EBUSY)
1170                 goto out_unlock;
1171         if (cdev->handler)
1172                 cdev->handler(cdev, cdev->private->intparm, ERR_PTR(-EIO));
1173         while (ret == -EBUSY) {
1174                 cdev->private->state = DEV_STATE_QUIESCE;
1175                 ret = ccw_device_cancel_halt_clear(cdev);
1176                 if (ret == -EBUSY) {
1177                         ccw_device_set_timeout(cdev, HZ/10);
1178                         spin_unlock_irq(sch->lock);
1179                         wait_event(cdev->private->wait_q,
1180                                    cdev->private->state != DEV_STATE_QUIESCE);
1181                         spin_lock_irq(sch->lock);
1182                 }
1183                 ret = cio_disable_subchannel(sch);
1184         }
1185 out_unlock:
1186         spin_unlock_irq(sch->lock);
1187 }
1188
1189 static void io_subchannel_shutdown(struct subchannel *sch)
1190 {
1191         io_subchannel_quiesce(sch);
1192 }
1193
1194 static int device_is_disconnected(struct ccw_device *cdev)
1195 {
1196         if (!cdev)
1197                 return 0;
1198         return (cdev->private->state == DEV_STATE_DISCONNECTED ||
1199                 cdev->private->state == DEV_STATE_DISCONNECTED_SENSE_ID);
1200 }
1201
1202 static int recovery_check(struct device *dev, void *data)
1203 {
1204         struct ccw_device *cdev = to_ccwdev(dev);
1205         int *redo = data;
1206
1207         spin_lock_irq(cdev->ccwlock);
1208         switch (cdev->private->state) {
1209         case DEV_STATE_DISCONNECTED:
1210                 CIO_MSG_EVENT(3, "recovery: trigger 0.%x.%04x\n",
1211                               cdev->private->dev_id.ssid,
1212                               cdev->private->dev_id.devno);
1213                 dev_fsm_event(cdev, DEV_EVENT_VERIFY);
1214                 *redo = 1;
1215                 break;
1216         case DEV_STATE_DISCONNECTED_SENSE_ID:
1217                 *redo = 1;
1218                 break;
1219         }
1220         spin_unlock_irq(cdev->ccwlock);
1221
1222         return 0;
1223 }
1224
1225 static void recovery_work_func(struct work_struct *unused)
1226 {
1227         int redo = 0;
1228
1229         bus_for_each_dev(&ccw_bus_type, NULL, &redo, recovery_check);
1230         if (redo) {
1231                 spin_lock_irq(&recovery_lock);
1232                 if (!timer_pending(&recovery_timer)) {
1233                         if (recovery_phase < ARRAY_SIZE(recovery_delay) - 1)
1234                                 recovery_phase++;
1235                         mod_timer(&recovery_timer, jiffies +
1236                                   recovery_delay[recovery_phase] * HZ);
1237                 }
1238                 spin_unlock_irq(&recovery_lock);
1239         } else
1240                 CIO_MSG_EVENT(4, "recovery: end\n");
1241 }
1242
1243 static DECLARE_WORK(recovery_work, recovery_work_func);
1244
1245 static void recovery_func(unsigned long data)
1246 {
1247         /*
1248          * We can't do our recovery in softirq context and it's not
1249          * performance critical, so we schedule it.
1250          */
1251         schedule_work(&recovery_work);
1252 }
1253
1254 static void ccw_device_schedule_recovery(void)
1255 {
1256         unsigned long flags;
1257
1258         CIO_MSG_EVENT(4, "recovery: schedule\n");
1259         spin_lock_irqsave(&recovery_lock, flags);
1260         if (!timer_pending(&recovery_timer) || (recovery_phase != 0)) {
1261                 recovery_phase = 0;
1262                 mod_timer(&recovery_timer, jiffies + recovery_delay[0] * HZ);
1263         }
1264         spin_unlock_irqrestore(&recovery_lock, flags);
1265 }
1266
1267 static int purge_fn(struct device *dev, void *data)
1268 {
1269         struct ccw_device *cdev = to_ccwdev(dev);
1270         struct ccw_dev_id *id = &cdev->private->dev_id;
1271
1272         spin_lock_irq(cdev->ccwlock);
1273         if (is_blacklisted(id->ssid, id->devno) &&
1274             (cdev->private->state == DEV_STATE_OFFLINE)) {
1275                 CIO_MSG_EVENT(3, "ccw: purging 0.%x.%04x\n", id->ssid,
1276                               id->devno);
1277                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1278         }
1279         spin_unlock_irq(cdev->ccwlock);
1280         /* Abort loop in case of pending signal. */
1281         if (signal_pending(current))
1282                 return -EINTR;
1283
1284         return 0;
1285 }
1286
1287 /**
1288  * ccw_purge_blacklisted - purge unused, blacklisted devices
1289  *
1290  * Unregister all ccw devices that are offline and on the blacklist.
1291  */
1292 int ccw_purge_blacklisted(void)
1293 {
1294         CIO_MSG_EVENT(2, "ccw: purging blacklisted devices\n");
1295         bus_for_each_dev(&ccw_bus_type, NULL, NULL, purge_fn);
1296         return 0;
1297 }
1298
1299 void ccw_device_set_disconnected(struct ccw_device *cdev)
1300 {
1301         if (!cdev)
1302                 return;
1303         ccw_device_set_timeout(cdev, 0);
1304         cdev->private->flags.fake_irb = 0;
1305         cdev->private->state = DEV_STATE_DISCONNECTED;
1306         if (cdev->online)
1307                 ccw_device_schedule_recovery();
1308 }
1309
1310 void ccw_device_set_notoper(struct ccw_device *cdev)
1311 {
1312         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1313
1314         CIO_TRACE_EVENT(2, "notoper");
1315         CIO_TRACE_EVENT(2, dev_name(&sch->dev));
1316         ccw_device_set_timeout(cdev, 0);
1317         cio_disable_subchannel(sch);
1318         cdev->private->state = DEV_STATE_NOT_OPER;
1319 }
1320
1321 enum io_sch_action {
1322         IO_SCH_UNREG,
1323         IO_SCH_ORPH_UNREG,
1324         IO_SCH_ATTACH,
1325         IO_SCH_UNREG_ATTACH,
1326         IO_SCH_ORPH_ATTACH,
1327         IO_SCH_REPROBE,
1328         IO_SCH_VERIFY,
1329         IO_SCH_DISC,
1330         IO_SCH_NOP,
1331 };
1332
1333 static enum io_sch_action sch_get_action(struct subchannel *sch)
1334 {
1335         struct ccw_device *cdev;
1336
1337         cdev = sch_get_cdev(sch);
1338         if (cio_update_schib(sch)) {
1339                 /* Not operational. */
1340                 if (!cdev)
1341                         return IO_SCH_UNREG;
1342                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1343                         return IO_SCH_UNREG;
1344                 return IO_SCH_ORPH_UNREG;
1345         }
1346         /* Operational. */
1347         if (!cdev)
1348                 return IO_SCH_ATTACH;
1349         if (sch->schib.pmcw.dev != cdev->private->dev_id.devno) {
1350                 if (ccw_device_notify(cdev, CIO_GONE) != NOTIFY_OK)
1351                         return IO_SCH_UNREG_ATTACH;
1352                 return IO_SCH_ORPH_ATTACH;
1353         }
1354         if ((sch->schib.pmcw.pam & sch->opm) == 0) {
1355                 if (ccw_device_notify(cdev, CIO_NO_PATH) != NOTIFY_OK)
1356                         return IO_SCH_UNREG;
1357                 return IO_SCH_DISC;
1358         }
1359         if (device_is_disconnected(cdev))
1360                 return IO_SCH_REPROBE;
1361         if (cdev->online)
1362                 return IO_SCH_VERIFY;
1363         return IO_SCH_NOP;
1364 }
1365
1366 /**
1367  * io_subchannel_sch_event - process subchannel event
1368  * @sch: subchannel
1369  * @process: non-zero if function is called in process context
1370  *
1371  * An unspecified event occurred for this subchannel. Adjust data according
1372  * to the current operational state of the subchannel and device. Return
1373  * zero when the event has been handled sufficiently or -EAGAIN when this
1374  * function should be called again in process context.
1375  */
1376 static int io_subchannel_sch_event(struct subchannel *sch, int process)
1377 {
1378         unsigned long flags;
1379         struct ccw_device *cdev;
1380         struct ccw_dev_id dev_id;
1381         enum io_sch_action action;
1382         int rc = -EAGAIN;
1383
1384         spin_lock_irqsave(sch->lock, flags);
1385         if (!device_is_registered(&sch->dev))
1386                 goto out_unlock;
1387         if (work_pending(&sch->todo_work))
1388                 goto out_unlock;
1389         cdev = sch_get_cdev(sch);
1390         if (cdev && work_pending(&cdev->private->todo_work))
1391                 goto out_unlock;
1392         action = sch_get_action(sch);
1393         CIO_MSG_EVENT(2, "event: sch 0.%x.%04x, process=%d, action=%d\n",
1394                       sch->schid.ssid, sch->schid.sch_no, process,
1395                       action);
1396         /* Perform immediate actions while holding the lock. */
1397         switch (action) {
1398         case IO_SCH_REPROBE:
1399                 /* Trigger device recognition. */
1400                 ccw_device_trigger_reprobe(cdev);
1401                 rc = 0;
1402                 goto out_unlock;
1403         case IO_SCH_VERIFY:
1404                 if (cdev->private->flags.resuming == 1) {
1405                         if (cio_enable_subchannel(sch, (u32)(addr_t)sch)) {
1406                                 ccw_device_set_notoper(cdev);
1407                                 break;
1408                         }
1409                 }
1410                 /* Trigger path verification. */
1411                 io_subchannel_verify(sch);
1412                 rc = 0;
1413                 goto out_unlock;
1414         case IO_SCH_DISC:
1415                 ccw_device_set_disconnected(cdev);
1416                 rc = 0;
1417                 goto out_unlock;
1418         case IO_SCH_ORPH_UNREG:
1419         case IO_SCH_ORPH_ATTACH:
1420                 ccw_device_set_disconnected(cdev);
1421                 break;
1422         case IO_SCH_UNREG_ATTACH:
1423         case IO_SCH_UNREG:
1424                 if (cdev)
1425                         ccw_device_set_notoper(cdev);
1426                 break;
1427         case IO_SCH_NOP:
1428                 rc = 0;
1429                 goto out_unlock;
1430         default:
1431                 break;
1432         }
1433         spin_unlock_irqrestore(sch->lock, flags);
1434         /* All other actions require process context. */
1435         if (!process)
1436                 goto out;
1437         /* Handle attached ccw device. */
1438         switch (action) {
1439         case IO_SCH_ORPH_UNREG:
1440         case IO_SCH_ORPH_ATTACH:
1441                 /* Move ccw device to orphanage. */
1442                 rc = ccw_device_move_to_orph(cdev);
1443                 if (rc)
1444                         goto out;
1445                 break;
1446         case IO_SCH_UNREG_ATTACH:
1447                 /* Unregister ccw device. */
1448                 if (!cdev->private->flags.resuming)
1449                         ccw_device_unregister(cdev);
1450                 break;
1451         default:
1452                 break;
1453         }
1454         /* Handle subchannel. */
1455         switch (action) {
1456         case IO_SCH_ORPH_UNREG:
1457         case IO_SCH_UNREG:
1458                 if (!cdev || !cdev->private->flags.resuming)
1459                         css_sch_device_unregister(sch);
1460                 break;
1461         case IO_SCH_ORPH_ATTACH:
1462         case IO_SCH_UNREG_ATTACH:
1463         case IO_SCH_ATTACH:
1464                 dev_id.ssid = sch->schid.ssid;
1465                 dev_id.devno = sch->schib.pmcw.dev;
1466                 cdev = get_ccwdev_by_dev_id(&dev_id);
1467                 if (!cdev) {
1468                         sch_create_and_recog_new_device(sch);
1469                         break;
1470                 }
1471                 rc = ccw_device_move_to_sch(cdev, sch);
1472                 if (rc) {
1473                         /* Release reference from get_ccwdev_by_dev_id() */
1474                         put_device(&cdev->dev);
1475                         goto out;
1476                 }
1477                 spin_lock_irqsave(sch->lock, flags);
1478                 ccw_device_trigger_reprobe(cdev);
1479                 spin_unlock_irqrestore(sch->lock, flags);
1480                 /* Release reference from get_ccwdev_by_dev_id() */
1481                 put_device(&cdev->dev);
1482                 break;
1483         default:
1484                 break;
1485         }
1486         return 0;
1487
1488 out_unlock:
1489         spin_unlock_irqrestore(sch->lock, flags);
1490 out:
1491         return rc;
1492 }
1493
1494 #ifdef CONFIG_CCW_CONSOLE
1495 static struct ccw_device console_cdev;
1496 static struct ccw_device_private console_private;
1497 static int console_cdev_in_use;
1498
1499 static DEFINE_SPINLOCK(ccw_console_lock);
1500
1501 spinlock_t * cio_get_console_lock(void)
1502 {
1503         return &ccw_console_lock;
1504 }
1505
1506 static int ccw_device_console_enable(struct ccw_device *cdev,
1507                                      struct subchannel *sch)
1508 {
1509         int rc;
1510
1511         /* Attach subchannel private data. */
1512         sch->private = cio_get_console_priv();
1513         memset(sch->private, 0, sizeof(struct io_subchannel_private));
1514         io_subchannel_init_fields(sch);
1515         rc = cio_commit_config(sch);
1516         if (rc)
1517                 return rc;
1518         sch->driver = &io_subchannel_driver;
1519         /* Initialize the ccw_device structure. */
1520         cdev->dev.parent= &sch->dev;
1521         sch_set_cdev(sch, cdev);
1522         io_subchannel_recog(cdev, sch);
1523         /* Now wait for the async. recognition to come to an end. */
1524         spin_lock_irq(cdev->ccwlock);
1525         while (!dev_fsm_final_state(cdev))
1526                 wait_cons_dev();
1527         rc = -EIO;
1528         if (cdev->private->state != DEV_STATE_OFFLINE)
1529                 goto out_unlock;
1530         ccw_device_online(cdev);
1531         while (!dev_fsm_final_state(cdev))
1532                 wait_cons_dev();
1533         if (cdev->private->state != DEV_STATE_ONLINE)
1534                 goto out_unlock;
1535         rc = 0;
1536 out_unlock:
1537         spin_unlock_irq(cdev->ccwlock);
1538         return rc;
1539 }
1540
1541 struct ccw_device *
1542 ccw_device_probe_console(void)
1543 {
1544         struct subchannel *sch;
1545         int ret;
1546
1547         if (xchg(&console_cdev_in_use, 1) != 0)
1548                 return ERR_PTR(-EBUSY);
1549         sch = cio_probe_console();
1550         if (IS_ERR(sch)) {
1551                 console_cdev_in_use = 0;
1552                 return (void *) sch;
1553         }
1554         memset(&console_cdev, 0, sizeof(struct ccw_device));
1555         memset(&console_private, 0, sizeof(struct ccw_device_private));
1556         console_cdev.private = &console_private;
1557         console_private.cdev = &console_cdev;
1558         ret = ccw_device_console_enable(&console_cdev, sch);
1559         if (ret) {
1560                 cio_release_console();
1561                 console_cdev_in_use = 0;
1562                 return ERR_PTR(ret);
1563         }
1564         console_cdev.online = 1;
1565         return &console_cdev;
1566 }
1567
1568 static int ccw_device_pm_restore(struct device *dev);
1569
1570 int ccw_device_force_console(void)
1571 {
1572         if (!console_cdev_in_use)
1573                 return -ENODEV;
1574         return ccw_device_pm_restore(&console_cdev.dev);
1575 }
1576 EXPORT_SYMBOL_GPL(ccw_device_force_console);
1577 #endif
1578
1579 /*
1580  * get ccw_device matching the busid, but only if owned by cdrv
1581  */
1582 static int
1583 __ccwdev_check_busid(struct device *dev, void *id)
1584 {
1585         char *bus_id;
1586
1587         bus_id = id;
1588
1589         return (strcmp(bus_id, dev_name(dev)) == 0);
1590 }
1591
1592
1593 /**
1594  * get_ccwdev_by_busid() - obtain device from a bus id
1595  * @cdrv: driver the device is owned by
1596  * @bus_id: bus id of the device to be searched
1597  *
1598  * This function searches all devices owned by @cdrv for a device with a bus
1599  * id matching @bus_id.
1600  * Returns:
1601  *  If a match is found, its reference count of the found device is increased
1602  *  and it is returned; else %NULL is returned.
1603  */
1604 struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
1605                                        const char *bus_id)
1606 {
1607         struct device *dev;
1608         struct device_driver *drv;
1609
1610         drv = get_driver(&cdrv->driver);
1611         if (!drv)
1612                 return NULL;
1613
1614         dev = driver_find_device(drv, NULL, (void *)bus_id,
1615                                  __ccwdev_check_busid);
1616         put_driver(drv);
1617
1618         return dev ? to_ccwdev(dev) : NULL;
1619 }
1620
1621 /************************** device driver handling ************************/
1622
1623 /* This is the implementation of the ccw_driver class. The probe, remove
1624  * and release methods are initially very similar to the device_driver
1625  * implementations, with the difference that they have ccw_device
1626  * arguments.
1627  *
1628  * A ccw driver also contains the information that is needed for
1629  * device matching.
1630  */
1631 static int
1632 ccw_device_probe (struct device *dev)
1633 {
1634         struct ccw_device *cdev = to_ccwdev(dev);
1635         struct ccw_driver *cdrv = to_ccwdrv(dev->driver);
1636         int ret;
1637
1638         cdev->drv = cdrv; /* to let the driver call _set_online */
1639
1640         ret = cdrv->probe ? cdrv->probe(cdev) : -ENODEV;
1641
1642         if (ret) {
1643                 cdev->drv = NULL;
1644                 return ret;
1645         }
1646
1647         return 0;
1648 }
1649
1650 static int
1651 ccw_device_remove (struct device *dev)
1652 {
1653         struct ccw_device *cdev = to_ccwdev(dev);
1654         struct ccw_driver *cdrv = cdev->drv;
1655         int ret;
1656
1657         if (cdrv->remove)
1658                 cdrv->remove(cdev);
1659         if (cdev->online) {
1660                 cdev->online = 0;
1661                 spin_lock_irq(cdev->ccwlock);
1662                 ret = ccw_device_offline(cdev);
1663                 spin_unlock_irq(cdev->ccwlock);
1664                 if (ret == 0)
1665                         wait_event(cdev->private->wait_q,
1666                                    dev_fsm_final_state(cdev));
1667                 else
1668                         CIO_MSG_EVENT(0, "ccw_device_offline returned %d, "
1669                                       "device 0.%x.%04x\n",
1670                                       ret, cdev->private->dev_id.ssid,
1671                                       cdev->private->dev_id.devno);
1672                 /* Give up reference obtained in ccw_device_set_online(). */
1673                 put_device(&cdev->dev);
1674         }
1675         ccw_device_set_timeout(cdev, 0);
1676         cdev->drv = NULL;
1677         return 0;
1678 }
1679
1680 static void ccw_device_shutdown(struct device *dev)
1681 {
1682         struct ccw_device *cdev;
1683
1684         cdev = to_ccwdev(dev);
1685         if (cdev->drv && cdev->drv->shutdown)
1686                 cdev->drv->shutdown(cdev);
1687         disable_cmf(cdev);
1688 }
1689
1690 static int ccw_device_pm_prepare(struct device *dev)
1691 {
1692         struct ccw_device *cdev = to_ccwdev(dev);
1693
1694         if (work_pending(&cdev->private->todo_work))
1695                 return -EAGAIN;
1696         /* Fail while device is being set online/offline. */
1697         if (atomic_read(&cdev->private->onoff))
1698                 return -EAGAIN;
1699
1700         if (cdev->online && cdev->drv && cdev->drv->prepare)
1701                 return cdev->drv->prepare(cdev);
1702
1703         return 0;
1704 }
1705
1706 static void ccw_device_pm_complete(struct device *dev)
1707 {
1708         struct ccw_device *cdev = to_ccwdev(dev);
1709
1710         if (cdev->online && cdev->drv && cdev->drv->complete)
1711                 cdev->drv->complete(cdev);
1712 }
1713
1714 static int ccw_device_pm_freeze(struct device *dev)
1715 {
1716         struct ccw_device *cdev = to_ccwdev(dev);
1717         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1718         int ret, cm_enabled;
1719
1720         /* Fail suspend while device is in transistional state. */
1721         if (!dev_fsm_final_state(cdev))
1722                 return -EAGAIN;
1723         if (!cdev->online)
1724                 return 0;
1725         if (cdev->drv && cdev->drv->freeze) {
1726                 ret = cdev->drv->freeze(cdev);
1727                 if (ret)
1728                         return ret;
1729         }
1730
1731         spin_lock_irq(sch->lock);
1732         cm_enabled = cdev->private->cmb != NULL;
1733         spin_unlock_irq(sch->lock);
1734         if (cm_enabled) {
1735                 /* Don't have the css write on memory. */
1736                 ret = ccw_set_cmf(cdev, 0);
1737                 if (ret)
1738                         return ret;
1739         }
1740         /* From here on, disallow device driver I/O. */
1741         spin_lock_irq(sch->lock);
1742         ret = cio_disable_subchannel(sch);
1743         spin_unlock_irq(sch->lock);
1744
1745         return ret;
1746 }
1747
1748 static int ccw_device_pm_thaw(struct device *dev)
1749 {
1750         struct ccw_device *cdev = to_ccwdev(dev);
1751         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1752         int ret, cm_enabled;
1753
1754         if (!cdev->online)
1755                 return 0;
1756
1757         spin_lock_irq(sch->lock);
1758         /* Allow device driver I/O again. */
1759         ret = cio_enable_subchannel(sch, (u32)(addr_t)sch);
1760         cm_enabled = cdev->private->cmb != NULL;
1761         spin_unlock_irq(sch->lock);
1762         if (ret)
1763                 return ret;
1764
1765         if (cm_enabled) {
1766                 ret = ccw_set_cmf(cdev, 1);
1767                 if (ret)
1768                         return ret;
1769         }
1770
1771         if (cdev->drv && cdev->drv->thaw)
1772                 ret = cdev->drv->thaw(cdev);
1773
1774         return ret;
1775 }
1776
1777 static void __ccw_device_pm_restore(struct ccw_device *cdev)
1778 {
1779         struct subchannel *sch = to_subchannel(cdev->dev.parent);
1780
1781         spin_lock_irq(sch->lock);
1782         if (cio_is_console(sch->schid)) {
1783                 cio_enable_subchannel(sch, (u32)(addr_t)sch);
1784                 goto out_unlock;
1785         }
1786         /*
1787          * While we were sleeping, devices may have gone or become
1788          * available again. Kick re-detection.
1789          */
1790         cdev->private->flags.resuming = 1;
1791         css_schedule_eval(sch->schid);
1792         spin_unlock_irq(sch->lock);
1793         css_complete_work();
1794
1795         /* cdev may have been moved to a different subchannel. */
1796         sch = to_subchannel(cdev->dev.parent);
1797         spin_lock_irq(sch->lock);
1798         if (cdev->private->state != DEV_STATE_ONLINE &&
1799             cdev->private->state != DEV_STATE_OFFLINE)
1800                 goto out_unlock;
1801
1802         ccw_device_recognition(cdev);
1803         spin_unlock_irq(sch->lock);
1804         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev) ||
1805                    cdev->private->state == DEV_STATE_DISCONNECTED);
1806         spin_lock_irq(sch->lock);
1807
1808 out_unlock:
1809         cdev->private->flags.resuming = 0;
1810         spin_unlock_irq(sch->lock);
1811 }
1812
1813 static int resume_handle_boxed(struct ccw_device *cdev)
1814 {
1815         cdev->private->state = DEV_STATE_BOXED;
1816         if (ccw_device_notify(cdev, CIO_BOXED) == NOTIFY_OK)
1817                 return 0;
1818         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1819         return -ENODEV;
1820 }
1821
1822 static int resume_handle_disc(struct ccw_device *cdev)
1823 {
1824         cdev->private->state = DEV_STATE_DISCONNECTED;
1825         if (ccw_device_notify(cdev, CIO_GONE) == NOTIFY_OK)
1826                 return 0;
1827         ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1828         return -ENODEV;
1829 }
1830
1831 static int ccw_device_pm_restore(struct device *dev)
1832 {
1833         struct ccw_device *cdev = to_ccwdev(dev);
1834         struct subchannel *sch;
1835         int ret = 0;
1836
1837         __ccw_device_pm_restore(cdev);
1838         sch = to_subchannel(cdev->dev.parent);
1839         spin_lock_irq(sch->lock);
1840         if (cio_is_console(sch->schid))
1841                 goto out_restore;
1842
1843         /* check recognition results */
1844         switch (cdev->private->state) {
1845         case DEV_STATE_OFFLINE:
1846         case DEV_STATE_ONLINE:
1847                 cdev->private->flags.donotify = 0;
1848                 break;
1849         case DEV_STATE_BOXED:
1850                 ret = resume_handle_boxed(cdev);
1851                 if (ret)
1852                         goto out_unlock;
1853                 goto out_restore;
1854         default:
1855                 ret = resume_handle_disc(cdev);
1856                 if (ret)
1857                         goto out_unlock;
1858                 goto out_restore;
1859         }
1860         /* check if the device type has changed */
1861         if (!ccw_device_test_sense_data(cdev)) {
1862                 ccw_device_update_sense_data(cdev);
1863                 ccw_device_sched_todo(cdev, CDEV_TODO_REBIND);
1864                 ret = -ENODEV;
1865                 goto out_unlock;
1866         }
1867         if (!cdev->online)
1868                 goto out_unlock;
1869
1870         if (ccw_device_online(cdev)) {
1871                 ret = resume_handle_disc(cdev);
1872                 if (ret)
1873                         goto out_unlock;
1874                 goto out_restore;
1875         }
1876         spin_unlock_irq(sch->lock);
1877         wait_event(cdev->private->wait_q, dev_fsm_final_state(cdev));
1878         spin_lock_irq(sch->lock);
1879
1880         if (ccw_device_notify(cdev, CIO_OPER) == NOTIFY_BAD) {
1881                 ccw_device_sched_todo(cdev, CDEV_TODO_UNREG);
1882                 ret = -ENODEV;
1883                 goto out_unlock;
1884         }
1885
1886         /* reenable cmf, if needed */
1887         if (cdev->private->cmb) {
1888                 spin_unlock_irq(sch->lock);
1889                 ret = ccw_set_cmf(cdev, 1);
1890                 spin_lock_irq(sch->lock);
1891                 if (ret) {
1892                         CIO_MSG_EVENT(2, "resume: cdev 0.%x.%04x: cmf failed "
1893                                       "(rc=%d)\n", cdev->private->dev_id.ssid,
1894                                       cdev->private->dev_id.devno, ret);
1895                         ret = 0;
1896                 }
1897         }
1898
1899 out_restore:
1900         spin_unlock_irq(sch->lock);
1901         if (cdev->online && cdev->drv && cdev->drv->restore)
1902                 ret = cdev->drv->restore(cdev);
1903         return ret;
1904
1905 out_unlock:
1906         spin_unlock_irq(sch->lock);
1907         return ret;
1908 }
1909
1910 static const struct dev_pm_ops ccw_pm_ops = {
1911         .prepare = ccw_device_pm_prepare,
1912         .complete = ccw_device_pm_complete,
1913         .freeze = ccw_device_pm_freeze,
1914         .thaw = ccw_device_pm_thaw,
1915         .restore = ccw_device_pm_restore,
1916 };
1917
1918 struct bus_type ccw_bus_type = {
1919         .name   = "ccw",
1920         .match  = ccw_bus_match,
1921         .uevent = ccw_uevent,
1922         .probe  = ccw_device_probe,
1923         .remove = ccw_device_remove,
1924         .shutdown = ccw_device_shutdown,
1925         .pm = &ccw_pm_ops,
1926 };
1927
1928 /**
1929  * ccw_driver_register() - register a ccw driver
1930  * @cdriver: driver to be registered
1931  *
1932  * This function is mainly a wrapper around driver_register().
1933  * Returns:
1934  *   %0 on success and a negative error value on failure.
1935  */
1936 int ccw_driver_register(struct ccw_driver *cdriver)
1937 {
1938         struct device_driver *drv = &cdriver->driver;
1939
1940         drv->bus = &ccw_bus_type;
1941         drv->name = cdriver->name;
1942         drv->owner = cdriver->owner;
1943
1944         return driver_register(drv);
1945 }
1946
1947 /**
1948  * ccw_driver_unregister() - deregister a ccw driver
1949  * @cdriver: driver to be deregistered
1950  *
1951  * This function is mainly a wrapper around driver_unregister().
1952  */
1953 void ccw_driver_unregister(struct ccw_driver *cdriver)
1954 {
1955         driver_unregister(&cdriver->driver);
1956 }
1957
1958 /* Helper func for qdio. */
1959 struct subchannel_id
1960 ccw_device_get_subchannel_id(struct ccw_device *cdev)
1961 {
1962         struct subchannel *sch;
1963
1964         sch = to_subchannel(cdev->dev.parent);
1965         return sch->schid;
1966 }
1967
1968 static void ccw_device_todo(struct work_struct *work)
1969 {
1970         struct ccw_device_private *priv;
1971         struct ccw_device *cdev;
1972         struct subchannel *sch;
1973         enum cdev_todo todo;
1974
1975         priv = container_of(work, struct ccw_device_private, todo_work);
1976         cdev = priv->cdev;
1977         sch = to_subchannel(cdev->dev.parent);
1978         /* Find out todo. */
1979         spin_lock_irq(cdev->ccwlock);
1980         todo = priv->todo;
1981         priv->todo = CDEV_TODO_NOTHING;
1982         CIO_MSG_EVENT(4, "cdev_todo: cdev=0.%x.%04x todo=%d\n",
1983                       priv->dev_id.ssid, priv->dev_id.devno, todo);
1984         spin_unlock_irq(cdev->ccwlock);
1985         /* Perform todo. */
1986         switch (todo) {
1987         case CDEV_TODO_ENABLE_CMF:
1988                 cmf_reenable(cdev);
1989                 break;
1990         case CDEV_TODO_REBIND:
1991                 ccw_device_do_unbind_bind(cdev);
1992                 break;
1993         case CDEV_TODO_REGISTER:
1994                 io_subchannel_register(cdev);
1995                 break;
1996         case CDEV_TODO_UNREG_EVAL:
1997                 if (!sch_is_pseudo_sch(sch))
1998                         css_schedule_eval(sch->schid);
1999                 /* fall-through */
2000         case CDEV_TODO_UNREG:
2001                 if (sch_is_pseudo_sch(sch))
2002                         ccw_device_unregister(cdev);
2003                 else
2004                         ccw_device_call_sch_unregister(cdev);
2005                 break;
2006         default:
2007                 break;
2008         }
2009         /* Release workqueue ref. */
2010         put_device(&cdev->dev);
2011 }
2012
2013 /**
2014  * ccw_device_sched_todo - schedule ccw device operation
2015  * @cdev: ccw device
2016  * @todo: todo
2017  *
2018  * Schedule the operation identified by @todo to be performed on the slow path
2019  * workqueue. Do nothing if another operation with higher priority is already
2020  * scheduled. Needs to be called with ccwdev lock held.
2021  */
2022 void ccw_device_sched_todo(struct ccw_device *cdev, enum cdev_todo todo)
2023 {
2024         CIO_MSG_EVENT(4, "cdev_todo: sched cdev=0.%x.%04x todo=%d\n",
2025                       cdev->private->dev_id.ssid, cdev->private->dev_id.devno,
2026                       todo);
2027         if (cdev->private->todo >= todo)
2028                 return;
2029         cdev->private->todo = todo;
2030         /* Get workqueue ref. */
2031         if (!get_device(&cdev->dev))
2032                 return;
2033         if (!queue_work(cio_work_q, &cdev->private->todo_work)) {
2034                 /* Already queued, release workqueue ref. */
2035                 put_device(&cdev->dev);
2036         }
2037 }
2038
2039 MODULE_LICENSE("GPL");
2040 EXPORT_SYMBOL(ccw_device_set_online);
2041 EXPORT_SYMBOL(ccw_device_set_offline);
2042 EXPORT_SYMBOL(ccw_driver_register);
2043 EXPORT_SYMBOL(ccw_driver_unregister);
2044 EXPORT_SYMBOL(get_ccwdev_by_busid);
2045 EXPORT_SYMBOL(ccw_bus_type);
2046 EXPORT_SYMBOL_GPL(ccw_device_get_subchannel_id);